Hi, I'm Adam Johansson

Welcome to my homepage! I'm a researcher focusing on the use of magnetic resonance imaging (MRI) to support radiation therapy (RT) of cancer. As a part of my early research I developed methods to convert MRI images to synthetic computed tomography (s-CT) images using MRI sequences with ultra-short echo time. These s-CTs were used for RT treatment planning and positron emission tomography (PET) attenuation correction. More recently, I have been working on motion-correction techniques for dynamic contrast-enhanced (DCE) MRI to improve liver perfusion and function measurements as well as reconstruction techinques to visualize gastrointestinal motion in support of adaptive RT.

More information here:



Liu L, Johansson A, Cao Y, Dow J, Lawrence TS, Balter JM. Abdominal synthetic CT generation from MR Dixon images using a U-Net trained with 'semi-synthetic' CT data. Phys Med Biol 2020;65(12):125001. https://doi.org/10.1088/1361-6560/ab8cd2

Johansson A, Balter JM, Cao Y. Abdominal DCE-MRI reconstruction with deformable motion correction for liver perfusion quantification. Med Phys 2018;45(10):4529-4540https://doi.org/10.1002/mp.13118

Simeth J, Johansson A, Owen D, Cuneo K, Mierzwa M, Feng M, Lawrence TS, Cao Y. Quantification of liver function by linearization of a two‐compartment model of gadoxetic acid uptake using dynamic contrast‐enhanced magnetic resonance imaging. NMR Biomed 2018;31:e3913. https://doi.org/10.1002/nbm.3913

Johansson A, Balter J, Cao Y. Rigid-body motion correction of the liver in image reconstruction for golden-angle stack-of-stars DCE MRI. Magn Reson Med 2018;79:1345–1353. https://doi.org/10.1002/mrm.26782

El Naqa I, Johansson A, Owen D, Cuneo K, Cao Y, Matuszak M, Bazzi L, Lawrence TS, Ten Haken RK. Modeling of Normal Tissue Complications Using Imaging and Biomarkers After Radiation Therapy for Hepatocellular Carcinoma. Int J Radiat Oncol Biol Phys 2018;100:335–343. https://doi.org/10.1016/j.ijrobp.2017.10.005

Lundman JA, Johansson A, Olofsson J, Axelsson J, Larsson A, Nyholm T. Effect of gradient field nonlinearity distortions in MRI-based attenuation maps for PET reconstruction. Phys Medica 2017;35:1–6. https://doi.org/10.1016/j.ejmp.2017.02.019

Johansson A, Balter J, Feng M, Cao Y. An overdetermined system of transform equations in support of robust DCE-MRI registration with outlier rejection. Tomography 2016;2:188–196. https://doi.org/10.18383/j.tom.2016.00145

Jonsson JH, Akhtari MM, Karlsson MG, Johansson A, Asklund T, Nyholm T. Accuracy of inverse treatment planning on substitute CT images derived from MR data for brain lesions. Radiat Oncol 2015;10:1–17. https://doi.org/10.1186/s13014-014-0308-1

Johansson A, Garpebring A, Asklund T, Nyholm T. CT substitutes derived from MR images reconstructed with parallel imaging. Med Phys 2014;41:82302-1–7. https://doi.org/10.1118/1.4886766

Larsson A, Johansson A, Axelsson J, Nyholm T, Asklund T, Riklund K, Karlsson M. Evaluation of an attenuation correction method for PET/MR imaging of the head based on substitute CT images. Magn Reson Mater Phys 2013;26:127–136. https://doi.org/10.1007/s10334-012-0339-2

Johansson A, Garpebring A, Karlsson M, Asklund T, Nyholm T. Improved quality of computed tomography substitute derived from magnetic resonance (MR) data by incorporation of spatial information - potential application for MR-only radiotherapy and attenuation correction in positron emission tomography. Acta Oncol 2013;52:1369–1373. https://doi.org/10.3109/0284186X.2013.819119

Lindström A, Andersson CD, Johansson A, Karlsson M, Nyholm T. Bone contrast optimization in magnetic resonance imaging using experimental design of ultra-short echo-time parameters. Chemom Intell Lab Syst 2013;125:33–39. https://doi.org/10.1016/j.chemolab.2013.03.011

Garpebring A, Brynolfsson P, Yu J, Wirestam R, Johansson A, Asklund T, Karlsson M. Uncertainty estimation in dynamic contrast-enhanced MRI. Magn Reson Med 2013;69:992–1002. https://doi.org/10.1002/mrm.24328

Jonsson JH, Johansson A, Söderström K, Asklund T, Nyholm T. Treatment planning of intracranial targets on MRI derived substitute CT data. Radiother Oncol 2013;108:118–122. https://doi.org/10.1016/j.radonc.2013.04.028

Johansson A, Karlsson M, Yu J, Asklund T, Nyholm T. Voxel-wise uncertainty in CT substitute derived from MRI. Med Phys 2012;39:3283–3290. https://doi.org/10.1118/1.4711807

Johansson A, Karlsson M, Nyholm T. CT substitute derived from MRI sequences with ultrashort echo time. Med Phys 2011;38:2708–2714. https://doi.org/10.1118/1.3578928


Johansson A, Balter J, Cao Y. Gastrointestinal 4D MRI with respiratory motion correction. Med Phys 2018;45:e583-e584. https://doi.org/10.1002/mp.12938

Liu L, Johansson A, Balter JM, Fessler JA, Cao Y. Accelerated high b-value diffusion-weighted MRI for higher-order diffusion analysis using a phase-constrained low-rank tensor model. Proc Intl Soc Magn Reson Med 2018;26:655. http://archive.ismrm.org/2017/0655.html

Johansson A, Balter J, Cao Y. Effects of reconstruction with deformable motion correction on abdominal DCE-MRI images. Proc Intl Soc Magn Reson Med 2018;26:475. http://archive.ismrm.org/2018/0475.html

Liu L, Johansson A, Balter JM, Cao Y, Fessler JA. Accelerated high b-value diffusion-weighted MR imaging via phase-constrained low-rank tensor model. IEEE International Symposium on Biomedical Imaging 2018;15:344-348. https://doi.org/10.1109/ISBI.2018.8363589

Owen D, Vineberg KA, Li P, Cao Y, Johansson A, Cuneo KC, Lawrence TS, Balter J. Utility of 4DMRI for Liver Radiation Planning. Int J Radiat Oncol 2017;99:S176–S177. https://doi.org/10.1016/J.IJROBP.2017.06.444

Johansson A, Balter J, Cao Y. Motion-corrected image reconstruction of abdominal DCE-MRI images. Proc Intl Soc Magn Reson Med 2017;25:1295. http://archive.ismrm.org/2017/1295.html

Johansson A, Balter J, Feng M, Cao Y. WE-FG-206-10: Portal Venous Perfusion Quantitation From Liver DCE-MRI by Voxel Uptake Curve Clustering and Input Function Normalization. Med Phys 2016;43:3833–3833. https://doi.org/10.1118/1.4957940

Jonsson J, Akhtari M, Karlsson M, Johansson A, Asklund T, Nyholm T. EP-1601: Accuracy of inverse treatment planning on substitute CT images derived from MR data in brain lesions. Radiother Oncol 2014;111:S203–S204. https://doi.org/10.1016/S0167-8140(15)31719-9

Johansson A, Garpebring A, Nyholm A. CT substitutes derived from SPIRiT and CG-SENSE reconstructed images. Proc Intl Soc Magn Reson Med 2013;21:1665. http://archive.ismrm.org/2013/1665.html

Johansson A, Karlsson M, Nyholm T. PO-0861 UNCERTAINTY IN CT SUBSTITUTE DERIVED FROM MRI. Radiother Oncol 2012;103:S336–S337. https://doi.org/10.1016/S0167-8140(12)71194-5

Jonsson J, Johansson A, Nyholm T. PO-0852 TREATMENT PLANNING BASED ON AUTOMATICALLY DENSITY MAPPED MR IMAGES. Radiother Oncol 2012;103:S333. https://doi.org/10.1016/S0167-8140(12)71185-4

Garpebring A, Brynolfsson P, Yu J, Wirestam R, Johansson A, Asklund T, Karlsson M. Uncertainty Maps in Dynamic Contrast-Enhanced MRI. Proc Intl Soc Magn Reson Med 2012;20:0242. http://archive.ismrm.org/2012/0242.html

Nyholm T, Johansson A, Karlsson M. 379 oral VOXEL BASED METHOD TO GENERATE CT EQUIVALENT IMAGES FROM MR IMAGES FOR TREATMENT PLANNING PURPOSES. Radiother Oncol 2011;99:S149–S150. https://doi.org/10.1016/S0167-8140(11)70501-1

Johansson A, Jonsson J, Karlsson M, Nyholm T. MRI Derived CT Substitute. Proc Intl Soc Magn Reson Med 2011;19:1116. http://archive.ismrm.org/2011/1116.html


Johansson A. Magnetic resonance imaging with ultrashort echo time as a substitute for X-ray computed tomography. PhD dissertation, Umeå University; 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-93053

Johansson A. Evaluation of Bone Contrast Enhanced MRI Sequences and Voxel Based Segmentation. Master's thesis, Umeå University; 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-37560

PS. Are you wondering what a rymdvinkel is? You can read about it in this Wikipedia article.